Auroras appear according to the whims of nature, not humans, which might just be part of their eerie appeal. But, c'mon, it's the 21st century now. Why are we just waiting around? So here's a crazy idea unearthed by Mark Zastrow writing in Eos: Let's build a particle accelerator to trigger auroras whenever we want.
By "we", I really mean scientists, who have written a serious theoretical paper modelling a particle accelerator that can shoot electron beams into space. Researchers at Stanford and SRI International have worked out the specs for the COMPASS, or the Compact Particle Accelerator for Space Science.
Picture: Marshall et al
To be clear, COMPASS does not exist, and the paper published a few months ago in the Journal of Geophysical Research does not address out the (many) logistical difficulties of building a particle accelerator in space. It does, however, outline how such a machine could work, giving scientists a radical new tool for studying how particles behave in Earth's magnetic field. Zastrow explains in Eos:
High above the Earth's surface, high-energy electrons and ions rain down on the atmosphere, spiraling along the planet's magnetic field lines. When they strike the upper atmosphere, they can excite or ionize nitrogen and oxygen molecules and produce glowing displays of auroras. However, one way to study this behaviour in even greater detail is to inject the electrons artificially with a spaceborne particle accelerator.
That's what Marshall et al. consider in a new study, which uses computer simulations to explore the capabilities of a small, but powerful, particle accelerator positioned at an altitude of 300 kilometers, aimed at the atmosphere.